Elastic-fluid turbine



F. HODGKINSON.

ELASTIC FLUID TURBINE- APPLICATION FILED JAN- 30. 1915.

IN VE N TOR.

HIS ATTORNEY IN FACT luuiran stares PATENT tJE-FIQE runners nonen nson,or snenwocn PARK,PENNSYLVA1\TIA, assienoa are when menousnnnncrnrc aMANUFACTURING COMPANY, a coaronarion or rennilti measure,

ELASTIC-FLUID TURBIJEIE.

' atcntedJuly (i, ltltith Application filed January 30, 1915. Serial No.5,249.

lie it known that 1, Francis l-looeninson,

a subject the liing of Great Britain and ciency of turbines by reducinglosses caused by the productionof eddy currents in the fluid passagesbetween the separate stages or sections of the turbine.

lurbines of the reaction type, are usually built in more than onediameter, and it is.

desirable that the fluid passages between the working sections ofdifferent diametersbe soarranged as to provide an easy passage for thefiuid without the production of objectionable countencurrents oreddiesand resultant losses in f, efliciency i Such fluid passages are locatedbetween the rotor and the stator elements and in turbineshaving highblade speeds, in which the blades are carried, for example, on disks orwheels, it is impossible to construct a rotor element having thenecessary contour to provide fluid passages of the desired shape,without materially increasing the weight of the rotor element. It willalso be apparent that the outer surface of the turbine rotor built up toform portions of different diameters cannot be constructed to provide asmooth and continuous surface between the working passages of differentdiameters without materially changing the rotor construction and addingmaterially to the weight of the rotor.

in accordance with my invention, ll form fluid pas ages between theseparate sections or stages of the turbine which are wholly locatedwithin stationary members and,

which, in the present embodiment of the invention, are shown mounted 011the stator element of the turbine.

In the single sheet drawing accompanying and forming a part hereof,Figure 1 is a fragmental longitudinal section of a turbine equipped withstationary fluid passages for delivering the motive fluid from sectionsof the working passage of smaller diameter to sections of largerdiameter.

, Fig, 2 is a transverse section through a stationary fluid passageon asmaller scale.

Referring to the drawing: T he rotor element illustrated consists of acylinder 3, bolted or otherwise secured to a wheel a, which as shown, isformed integrally with a drum 5, on which two wheels 6 and 7 aremounted. The peripheral face of the cylinder 3,011 which the blades orbuckets 8 are mounted, is of less diameter than the blade carrying rim 9of the wheel fl, and this rim is of less diameter than the bladecarrying rims 10 of the wheels 6 and 7. Consequently, the portion of therotor element shown, is equipped with three sets of blades, each ofwhlch iorms a separate working section of the turbine of diiferentdiameter from the other two.

The stator 11 inclosing the rotor is of I usual construction and isformed in two sections, as is customary. lts inner face correspondsgenerally to the contour of the turhine," rotor and is of such diameterto pro recting vanes 12 are located. Inasmuch as the stator increases indiameter from the admission end of the turbine to the exhaust end and,inasmuch as the working blades of the turbine increase in length towardthe exhaust end of the turbine but are arranged in groups includingseveral rows of blades or vanes of the same length, it is customary toincrease the diameter of the stator in steps corresponding somewhat tothe step formation of the rotor.

In turbines having high blade speeds practice indicates the advisabilityof mounting the blades on wheels or disks, since such a constiuictionprovides the necessary strength without unduly increasing the weight ofthe rotor element. Rotors constructed in this manner with wheels ordisks of different diameters form pockets or sharp ion the other inwhich there are no pockets or sharp turns capable of producing retardingor eddying currents in the motive fluid.

In the present embodiment of the inventionthese passages are formed inseparate annular members 13, which, as shown, are bolted or otherwisesecured to the stator and are formed in sections corresponding to thesections of the stator. Each member 13 is provided with an annular fluidpassage let, which is adapted to receive motive fluid issuing from theblades of one section and to direct it into the blades of the nextadjacent section. The annular inlet to the passage A may be of lessdiameter than the outlet and the walls of the passage are curved so asto direct the fluid to the section of larger diameter with minimumlosses due to friction or reversal in flow. As illustrated, the innerwall 15' of the passage is secured to the outer wall by means or"radially extending webs 16, which are preferably located so as toconform to the direction of flow ot the steam through the passage.

In other words, the webs 1.6 will be so located that they will besubstantially parallel to the direction of flow of the steam or motivefluid issuing from the last row of blades delivering steam or fluid tothe passage 2-1. As illustrated, the member l3 is so formed that itsouter wall in effeet forms a continuation of the inner surface of thestator between the portions of different diameters, and the inner wallin effect forms a continuation of the peripheral face of the rotorbetween portions of different diameters, a small clearance only beingmaintained between it and each adjacent portion of the rotor.

It will be apparent that these passages .14 may be formed within thestator element and that various changes, modifications, substitutions,additions and omissions may be made in the apparatus illustrated withoutdeparting from the spirit and scope of my invention.

\Vhat I claim is:

A fluid conduit member for turbines having spaced rotor elements,comprising a pair of concentrically disposed stationam annular wallsadapted to fit between the rotor elements, and having their outsilesurfaces conforming in contour to their inside. surfaces, and havingtheir inside surface curved to form a passage oll'ering minimumresistance to the flow oi fluid from one rotor of small diameter to arotor oi larger diameter, the outer wall of the said member beingprovided with a radially extending flange whereby the member is securedto the turbine stator and the inner wall being connected to the outerwall by fluiil directing vanes whereby the inner wall is supported bythe outer wall.

In testimony whereof l have hereunto subscribed my name this 21st day ofJanuary, 1915.

FRANClS HODGKINSON.

itnesses (J. V. MeGrinm, it. M. MoGALLrsTER.

